Mary is a nomadic vampire and a friend of Carlisle and Randall. Emmett and Rosalie send Mary to help. She listens to Renesmee’s story and agrees to be a witness. (BD32) Mary has not decided to fight the Volturi if it comes to that. (BD34)

At the clearing, the witnesses cluster to the left and right of the members of the Cullens and Denali clan that make up the front line. (BD35) With the arrival of Alice and other witnesses, the situation is resolved, and the Volturi leave. (BD38) Mary quickly leaves after that. (BD39)